Transient Ischemic Attack (TIA), often referred to as a “mini-stroke,” is a temporary period of symptoms similar to those of a stroke. A TIA usually lasts only a few minutes and doesn’t cause permanent damage. It’s often caused by a temporary decrease in blood supply to part of the brain, which may indicate a serious risk for a future stroke.
Causes of Transient Cerebral Ischemia:
- Embolism from the Heart: Atrial fibrillation, heart valve disease, or recent myocardial infarction can lead to clot formation.
- Large Artery Atherosclerosis: Plaques in major brain arteries can lead to symptomatic emboli.
- Small Vessel Disease: Affects smaller penetrating brain arteries.
- Other Causes: Include blood disorders (e.g., polycythemia, sickle cell disease), arterial dissection, and vasospasm.
Diagnosis:
- History:
- Rapid onset of symptoms.
- Typical symptoms: temporary loss of vision (amaurosis fugax), speech disturbance, weakness or numbness of one side of the body, dizziness, and difficulty with coordination.
- Duration: Symptoms usually last less than an hour.
- Risk factors: hypertension, diabetes, smoking, hyperlipidemia, atrial fibrillation.
- Physical Examination:
- Neurological examination: Often normal in TIA; however, may reveal transient deficits corresponding to the vascular territory involved.
- Cardiovascular examination: To identify potential sources of embolism (e.g., irregular heartbeat in AF).
- Investigations:
- Blood Tests: Including lipid profile, blood glucose, complete blood count, and coagulation studies.
- Electrocardiogram (ECG): To identify arrhythmias, particularly atrial fibrillation.
- Imaging: Immediate brain imaging (preferably MRI) to differentiate TIA from stroke and identify any underlying pathology.
- Carotid Ultrasound: To assess for carotid artery stenosis.
- Echocardiography: To identify cardiac sources of emboli.
Differential Diagnosis (DDx):
- Stroke
- Migraine with aura
- Seizure
- Hypoglycemia
- Psychiatric disorders (e.g., conversion disorder)
Management of TIA:
- Acute Management:
- Immediate assessment in an emergency setting.
- Antiplatelet therapy (e.g., aspirin) unless contraindicated.
- Management of risk factors: Blood pressure control, lipid-lowering therapy, diabetes management.
- Secondary Prevention:
- Long-term antiplatelet therapy (e.g., aspirin, clopidogrel).
- Anticoagulation in cases with atrial fibrillation.
- Lifestyle modifications: Smoking cessation, diet, exercise.
- Carotid endarterectomy or stenting in cases with significant carotid stenosis.
- Risk Factor Management:
- Hypertension control
- Diabetes control.
- Statins for lipid management.
- Lifestyle changes to reduce stroke risk ie cease smoking
- Education and Rehabilitation:
- Educate patients about stroke symptoms and the importance of prompt medical attention.
- Referral for rehabilitation if any deficits persist.
Conclusion:
A TIA is a medical emergency, as it can be a precursor to a stroke. Prompt evaluation and management are crucial, including risk factor modification and secondary prevention strategies to reduce the risk of future strokes. Regular follow-up is essential to monitor and manage ongoing risk factors.